Trim the root end of the leeks but not completely. Leave enough for the leek to stay in tact. Then cut the last couple inches of the dark greens.
Without cutting the root end, slice the leeks in half lengthwise, give them a quarter turn and slice lengthwise again.
Rinse them under running water to remove all the grit in-between the leaves.
Place the leeks in a large skillet and add the chicken stock, butter, half the parsley, and salt and pepper. Bring to a boil, cover, leave a crack for evaporation, and then simmer until soft, about 20 minutes.
Sprinkle with the remainder of the parsley just before serving.
(Calorie counters: Skip the butter and use low fat chicken broth).